From 0e57d709e93c44f31a13722b224bc8324b9ed5ea Mon Sep 17 00:00:00 2001
From: Michael Kruse <llvm@meinersbur.de>
Date: Tue, 18 Aug 2015 12:17:37 +0000
Subject: [PATCH] [Support] On Windows, generate PDF files for graphs and open
 with associated viewer

Summary: Windows system rarely have good PostScript viewers installed, but PDF viewers are common. So for viewing graphs, generate PDF files and open with the associated PDF viewer using cmd.exe's start command.

Reviewers: Bigcheese, aaron.ballman

Subscribers: aaron.ballman, JakeVanAdrighem, dwiberg, llvm-commits

Differential Revision: http://reviews.llvm.org/D11877

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245290 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Support/GraphWriter.cpp | 72 +++++++++++++++++++++++++------------
 1 file changed, 49 insertions(+), 23 deletions(-)

diff --git a/lib/Support/GraphWriter.cpp b/lib/Support/GraphWriter.cpp
index 0bbfde232a1..cbf53493337 100644
--- a/lib/Support/GraphWriter.cpp
+++ b/lib/Support/GraphWriter.cpp
@@ -189,61 +189,87 @@ bool llvm::DisplayGraph(StringRef FilenameRef, bool wait,
     return ExecGraphViewer(ViewerPath, args, Filename, wait, ErrMsg);
   }
 
-  enum PSViewerKind { PSV_None, PSV_OSXOpen, PSV_XDGOpen, PSV_Ghostview };
-  PSViewerKind PSViewer = PSV_None;
+  enum ViewerKind {
+    VK_None,
+    VK_OSXOpen,
+    VK_XDGOpen,
+    VK_Ghostview,
+    VK_CmdStart
+  };
+  ViewerKind Viewer = VK_None;
 #ifdef __APPLE__
-  if (!PSViewer && S.TryFindProgram("open", ViewerPath))
-    PSViewer = PSV_OSXOpen;
+  if (!Viewer && S.TryFindProgram("open", ViewerPath))
+    Viewer = VK_OSXOpen;
+#endif
+  if (!Viewer && S.TryFindProgram("gv", ViewerPath))
+    Viewer = VK_Ghostview;
+  if (!Viewer && S.TryFindProgram("xdg-open", ViewerPath))
+    Viewer = VK_XDGOpen;
+#ifdef LLVM_ON_WIN32
+  if (!Viewer && S.TryFindProgram("cmd", ViewerPath)) {
+    Viewer = VK_CmdStart;
+  }
 #endif
-  if (!PSViewer && S.TryFindProgram("gv", ViewerPath))
-    PSViewer = PSV_Ghostview;
-  if (!PSViewer && S.TryFindProgram("xdg-open", ViewerPath))
-    PSViewer = PSV_XDGOpen;
 
-  // PostScript graph generator + PostScript viewer
+  // PostScript or PDF graph generator + PostScript/PDF viewer
   std::string GeneratorPath;
-  if (PSViewer &&
+  if (Viewer &&
       (S.TryFindProgram(getProgramName(program), GeneratorPath) ||
        S.TryFindProgram("dot|fdp|neato|twopi|circo", GeneratorPath))) {
-    std::string PSFilename = Filename + ".ps";
+    std::string OutputFilename =
+        Filename + (Viewer == VK_CmdStart ? ".pdf" : ".ps");
 
     std::vector<const char *> args;
     args.push_back(GeneratorPath.c_str());
-    args.push_back("-Tps");
+    if (Viewer == VK_CmdStart)
+      args.push_back("-Tpdf");
+    else
+      args.push_back("-Tps");
     args.push_back("-Nfontname=Courier");
     args.push_back("-Gsize=7.5,10");
     args.push_back(Filename.c_str());
     args.push_back("-o");
-    args.push_back(PSFilename.c_str());
+    args.push_back(OutputFilename.c_str());
     args.push_back(nullptr);
 
     errs() << "Running '" << GeneratorPath << "' program... ";
 
-    if (ExecGraphViewer(GeneratorPath, args, Filename, true, ErrMsg))
+    if (ExecGraphViewer(GeneratorPath, args, Filename, wait, ErrMsg))
       return true;
 
+    // The lifetime of StartArg must include the call of ExecGraphViewer
+    // because the args are passed as vector of char*.
+    std::string StartArg;
+
     args.clear();
     args.push_back(ViewerPath.c_str());
-    switch (PSViewer) {
-    case PSV_OSXOpen:
+    switch (Viewer) {
+    case VK_OSXOpen:
       args.push_back("-W");
-      args.push_back(PSFilename.c_str());
+      args.push_back(OutputFilename.c_str());
       break;
-    case PSV_XDGOpen:
+    case VK_XDGOpen:
       wait = false;
-      args.push_back(PSFilename.c_str());
+      args.push_back(OutputFilename.c_str());
       break;
-    case PSV_Ghostview:
+    case VK_Ghostview:
       args.push_back("--spartan");
-      args.push_back(PSFilename.c_str());
+      args.push_back(OutputFilename.c_str());
+      break;
+    case VK_CmdStart:
+      args.push_back("/S");
+      args.push_back("/C");
+      StartArg =
+          (StringRef("start ") + (wait ? "/WAIT " : "") + OutputFilename).str();
+      args.push_back(StartArg.c_str());
       break;
-    case PSV_None:
+    case VK_None:
       llvm_unreachable("Invalid viewer");
     }
     args.push_back(nullptr);
 
     ErrMsg.clear();
-    return ExecGraphViewer(ViewerPath, args, PSFilename, wait, ErrMsg);
+    return ExecGraphViewer(ViewerPath, args, OutputFilename, wait, ErrMsg);
   }
 
   // dotty
-- 
2.34.1